Risso's dolphin

Risso's dolphins, also known as Monk dolphins, are the sole representatives of the genus Grampus. They were named after Antoine Risso, with their physical characteristics first described by Georges Cuvier in 1812. These dolphins present a distinct appearance, characterized by a large anterior body, a prominent dorsal fin, and a slender tail. Their skin is mottled grey and typically becomes heavily scarred as they age.

Risso's dolphins primarily feed on squid and inhabit temperate and tropical waters worldwide, usually favoring the deeper waters near the continental shelf. Socially, these dolphins exhibit complex behaviors. They often travel in groups ranging from 10 to 51 members and sometimes form even larger groups called "super-pods." Additionally, they are known to interact with other cetacean species and engage in activities such as surfing on bow waves.

Reproduction in Risso's dolphins involves a gestation period of 13 to 14 months, with the timing of calving varying by region. Unfortunately, these dolphins are threatened by several human activities, including entanglement in fishing gear, pollution, and small-scale whaling.

Efforts to protect Risso's dolphins include their inclusion in international agreements like the Convention on the Conservation of Migratory Species of Wild Animals and the Marine Mammal Protection Act in the United States. Despite these protective measures, they are still hunted in some countries, including Japan, Indonesia, the Solomon Islands, and the Lesser Antilles. Strandings of Risso's dolphins have been linked to factors such as parasitic infections and stress related to capture.